In the prior art, document EP 0 473 994 A2 is already known, which describes a reservoir in the form of a flexible shell containing a flexible pouch that is associated with a dispenser valve that includes a flexible membrane that is perforated with an orifice that is closed by a pin. When the flexible outer shell is squeezed, the flexible inner pouch is also deformed, such that the fluid that it contains is put under pressure and forced towards the dispenser valve where it lifts the flexible membrane off from the pin. In greater detail, the flexible pouch defines an opening that is heat-sealed onto a rigid pouch support that is engaged in a rigid neck formed by the outer shell. The pouch support is held in place on the neck of the shell by the dispenser valve that is screw-fastened on a thread formed by the outer wall of the neck of the shell.
Thus, fabricating the reservoir of that dispenser requires a flexible pouch to be heat-sealed onto a rigid pouch support, and then requires the flexible pouch to be inserted through the rigid neck of the outer shell. Finally, the dispenser valve is screw-fastened on the neck of the outer shell.
An intermediate gap is thus formed between the pouch and the shell. The intermediate gap communicates with the outside through vent channels formed by the pouch support and the dispenser valve. The provision of the vent path for venting the intermediate gap is particularly complicated.